Suitable magnetizable particles are referred to hereafter by way of example as “Fe3O4”, which is intended in a representative sense and also includes other suitable compounds or alloys. Suitable ores of value are referred to hereafter by way of example as Cu2S, which is intended in a representative sense and also includes other ores of value.
Ores of value, such as for example copper sulfide (Cu2S), are obtained by way of ore extraction. In order to separate the copper sulfide from the ore, the ore is first finely ground until it is in a virtually pulverulent form. Subsequently, in order to make magnetic separation of the Cu2S possible, magnetite (Fe3O4) and agents containing other chemical additives which have a hydrophobizing effect on the Cu2S and the Fe3O4 are added to the ore. This hydrophobization occurs as a result of the longer organic molecular chains that are contained in the additives and selectively become attached to the Cu2S or the Fe3O4. The latter are consequently surrounded with a water-repellent shell. These organic molecular chains then bring about an organic bond between the Cu2S and the magnetite, so as to produce Cu2S/Fe3O4 agglomerates that are magnetic (unlike pure Cu2S) and, as a result, can be separated from the rest of the fine powder, which substantially contains sand, by means of magnets. This means that these Cu2S/Fe3O4 particles can be extracted as a whole from the remaining material. Since, however, the Cu2S and Fe3O4 particles are of a size that is in the μm range, they have a tendency to agglomerate, that is to say that relatively large, cluster-like agglomerates form from one or more Cu2S particles and a multitude of Fe3O4 particles, the Cu2S particles being bonded to the Fe3O4 particles by way of the organic molecular chains. Within this particle agglomerate, the Cu2S particles are enclosed virtually completely by Fe3O4 particles; the organic molecular chains are situated between the Fe3O4 particles and the Cu2S particles. So, to be able to separate the pure Cu2S, it is necessary to break up this organic bond and to obtain the individual particles again, so that the Fe3O4 can once again be mechanically separated from the Cu2S. This has previously been performed by chemical means, that is to say it is attempted to break down the molecular chains by a suitable chemical process. As a result of the virtually complete enclosure of the Cu2S particles with Fe3O4 particles, there is the problem that the agents that are intended to react with the organic molecular chains can scarcely come into contact with these organic bonds for which reason the particle separation that can be achieved in this way is only relatively low.